Two established techniques for correcting the root cause of the heart rhythm disorder atrial fibrillation show similar effects and safety outcomes, according to research presented at the American College of Cardiology’s 65th Annual Scientific Session.
The study, called FIRE AND ICE, is the largest randomized trial to compare radiofrequency and cryoballoon ablation, two techniques designed to treat atrial fibrillation by disabling small portions of the heart that generate out-of-sync electrical signals. Radiofrequency ablation uses heat energy to disable the targeted heart tissue, while the cryoballoon, a newer technique, uses extreme cold to achieve the same effect. The trial revealed no differences between the two techniques for the study’s primary outcomes–the recurrence of an irregular heart rhythm or the need for medication or subsequent procedures to address atrial fibrillation. It was funded in part by Medtronic, which makes the cryoballoon device.
“The FIRE AND ICE trial demonstrated that the cryoballoon, a newer, easier-to-use ablation catheter, worked as well as the established technology, which ultimately means that more patients can be treated for atrial fibrillation without having [to go to a] specialized cardiac center,” said Karl-Heinz Kuck, M.D., Ph.D., head of cardiology at St. Georg Hospital in Hamburg, Germany, and the study’s lead author. “In addition, there was, in general, a low risk of procedural complications in both groups, demonstrating that catheter ablation has become much safer over the years.”
Atrial fibrillation, estimated to affect more than 33 million people worldwide, is an irregular heart rhythm that can cause fatigue, lightheadedness, shortness of breath, chest pain and an increased risk for stroke. Although medications and lifestyle changes can help manage the condition’s risk factors and symptoms, about 30 percent of patients do not benefit from available medications or cannot take them due to side effects or other reasons. Ablation is one option for treating these patients. During ablation, a physician threads a small medical device through a vein in the groin to kill a small number of cells around the heart’s pulmonary veins, preventing them from issuing electrical signals that are out of sync with the rest of the heart.
The trial, conducted in eight European countries, enrolled 769 patients needing ablation for intermittent atrial fibrillation. Patients were randomly assigned to receive either the radiofrequency or cryoballoon technique; both patients and physicians were aware of which technique was being used. The two groups were similar in terms of demographic factors, such as age and gender, as well as health status, based on parameters such as body mass index, blood pressure and various measures of heart function.